HAMILTON SCIENTIFIC ASSOCIATION. 57 



Plaskett, B.A. It consisted of a 20-inch coelostat (made by Prof. 

 John A. Brashear, of Alleghenj-) feeding (i) a 5-inch Grubh teles- 

 cope, 45 feet focus, producing a solar image five inches in diam- 

 eter ; (2) a 4-inch Grubb, 10 feet focus, giving an image of the 

 sun i^ inches in diameter ; (3J a Cooke photovisual, 4^ inch 

 aperture, 8 foot focus, giving a solar image ^ inch ; (4) prismatic 

 cameras. 



The Greenwich outfit consisted (i) of one-half of one photo- 

 heliograph used in the transit of Venus expedition, 1874, aperture 

 4 inches, focus 5 feet, used with one enlarging lens so as to give 

 an equivalent focus of 22 feet, and resulting in an image of 2.4 

 inches diameter. This was mounted on an equatorial stand, clock 

 driven. This instrument was operated by Mr. Maunder. (2) Abney 

 lens ; R. R. 4 inches, aperture 34-inch focus mounted on equa- 

 torial, clock driven, belonging to Mr. F. Jennings — Mr. Jennings 

 in charge. (3) Cooke photovi.sual, 3)^-inch aperture, 4-foot focus. 

 This was equatorially mounted, clock driven, and was operated by 

 Mr. Chas. Upton, of England. (4) Dallmeyer lens, i^ inches in 

 diameter, used by Mrs. Maunder in India in 1898, mounted on 

 small equatorial, clock driven, known as the pocket equatorial. It 

 was with this instrument that Mrs. Maunder succeeded in photo- 

 graphing the longest coronal streamer ever known, during the In- 

 dian eclipse of 1898. (5) Goerz lens, 2>^-inch aperture, 2-foot 

 focus, mounted as a fixed camera. Prof. Turner had an identical 

 instrument lent bj^ Mr. Goerz with which to photograph the 

 eclipse in Egypt at the other end of totality. 



The Hamilton contingent had the following equipment, a cut 

 of which accompanies this article : 



I. A 5-inch Brashear, 75-inch focus, equatorially mounted, 

 clock driven. This instrument gave an image of the sun ^ inch 

 in diameter at prime focus, but by the introduction of a negative 

 enlarging lens, which could be introduced or removed in five sec- 

 onds, the solar image was increased to three inches. With this 

 it was intended to photograph the partial phases of the eclipse, es- 

 pecially at the moment when the lunar limb came in contact with 

 sun spots, in order to contrast the darkness of the sun spots with 



